Isekai Hotel e Youkoso: Mazoku de Yuusha na Saikyou Ane-tachi kara Dekiaisarete Komattemasu

Richii's parents died in an accident when he was in junior high school, leaving him alone with his doting sister Towa. Three years later, his sister also disappears, and even Riichi is summoned to another world where he is reunited with his sister. In the other world, Towa has become the most powerf